Differences

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--- ntb:motors_init [2019/12/01 07:54] – created graf
+++ ntb:motors_init [2023/05/25 14:47] (current) – [Mechanical Limits of the Tool Center Point Motor] ursgraf
@@ Line 1: / Line 1: @@
 ====== Initialization - Zero reference ======
-The ''Calibration Sequence'' can be started by triggering the safety event ''doCalibrating''. This can be done by pressing the red button until this lights up. Press and hold the red button for 2 seconds, this will trigger the Safety Event ''doCalibrating''. When finished with calibrating, press the red button once again. Press the green button to get back in normal operation mode.
+The initialization for the axis motors is the same as [[:motors_init|]] with the additional motor for the TCP.
-==== Mechanical Limits of the Axis Motors - Upper limit ====
+==== Mechanical Limits of the Tool Center Point Motor ====
+The TCP rotation is limited by two metall pins. The maximum turn angle is calculated as follows:\\
+{{ :delta:ntb:software:tcp-limit.jpg?300 |TCP limit}}
-|{{:delta:zero_ref_ntb.jpg?350|}}|{{:delta:zero_ref_ntb_2.jpg?250|Upper limit calculation detail}}|
+  sin(γ/2) = r/R
-|Upper limit calculation shown below| Upper limit calculation detail |
+  γ=2*arcsin(r/R)= 0.0600 (rad) = 3.438°
+That is the value for one side. The other side is identical, so the maximum turn angle is
-L = 17.5 \\
+  β = 2*PI - 2 * 0.06 = 6.16 (rad) ≅ 353°
-B = 15   \\
-s = 4    \\
-The upper limit can be calculated as follows:
-\\ \\
-//(1) tan(β) = sin(β)/cos(β) = (B-y)/L// \\
-//(2) cos(β) = s/y// \\
-\\
-Substitute (2) into (1) to get: \\
-\\
-//(3) L*sin(β)-B*cos(β)=-s// \\
-\\
-Using following trigonometric formulas in (3):
-\\ \\
-//(4) t = tan(β/2) // \\
-//(5) sin(β) = 2*tan(β/2)/(1+tan^2(β/2) // \\
-//(6) sin(β) = (1-tan^2(β/2)/(1+tan^2(β/2) // \\
-\\
-Leads to:
-\\ \\
-//(7) (s+B)*t^2 + 2*L*t + (s-B) = 0// \\
-\\
-Solutions are:
-\\
-// t1 = 0.2736 -> β = 30.6°// \\
-// t2 = -2.1157 (neg. solution)// \\
-\\
-Hence, the maximum angle the axis can turn is // 90° + β ≅ 120°//.\\
-\\
-==== Mechanical Limits of the Axis Motors - Lower limit ====
-{{:delta:motor-axis-calculation-lower-n.jpg?300|}}
-Lower limit of the Axis Motor measured on the Delta robot, γ is about 5°.
-==== Mechanical Limits of the Tool Center Point Motor ====
-The TCP rotation is also limited by two metall pins. The maximum turn angle is calculated as follows:\\
-{{ :delta:tcp-limit.jpg?300 |TCP limit}}
-//sin(γ/2) = r/R//\\
+Zero position is chosen in the middle of the free range.
-//γ=2*arcsin(r/R)= 0.0600 (rad) = 3.438°//\\
-\\
-That is the value for one side. The other side is identical, so the maximum turn angle is\\
-\\
-//β = 2*PI - 2 * 0.06 = 6.16 (rad) ≅ 353°//.
+:!: Make sure that the TCP is properly fixed on the motor shaft. Two tiny screws must be carefully tightened.